Library not registered.

Opened a database that I don't use frequently, was prompted to update and did so. I attempted to create a new template for a letter and I received the error message "Unable to cast COM object of type "Microsoft.Office.Interop.Word.ApplicationClass'... After doing some research, I ran Detect & Repair in word. Now, in Act, I get the error message "Library not registered. Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)).